Attachment plug



Nov; 18 9 1,516,415

. G. B. THOMAS ATTACHMENT PLUG Filed Nov. 20, 1919 anue'ntoz (fear-ms 13. THO/v1 as flit 0144033 Patented Nov. 18, 192 44 Umrso STATES.

PATENT OFFICE.

GEOBGE B. THOMAS, BRIDOEPORT, CONNECTICUT, ASSIGNOR'TO THE BRYANT ELEC- TBIC COMPANY, OF BRIDGEPOBT, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ATTACHMENT PLUG.

Application filed November 20,1919. Serial No. 339,286.

T 0 all whom it may concern:

Be it known that I, Gnome B. THOMAS, a citizen of the United States of America, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Attachment Plugs, of which the following is a specification.

My invention relates to attachment plugs, and particularly to the jack-receiving terminals thereof, the object of my invention being to provide a plug of improved terminal construction adapted to cooperate with jacks of different types and spacings so as to render the plug substantially universal in its utility. y

In the accompanying drawings Fig. 1 is' a broken elevation of a plug in which my invention is embodied in one form;

Figs. 2 and 3 are sections on the lines '2'-2 and 33 of' Fig. 1; and

Fig. 4 is a dropped perspective of one' of the terminals.

The attachment plug to which my invention relates is of the type in which theterminals are connected to a source of electric current which they deliver to an appliance such as a toaster, chafing-dish, percolator, or the like in which the current is utilized. It is necessary for safety, therefore, that the terminals be housed in an insulating casing. It often happens that in fittings of difierent makes, the jacks are space apart different distances, or are of difierent types, such as blades rathertha-n posts. object of my invention to provide an attachment plug, the terminals of which are adapted to cooperate with either type of jacks, and to so arrange the terminals that hey float and are thus free to accommo-.

' date themselves to jacks of different spacings,

while at the same time maintaining good electrical connection" with the conductors with which the terminals are associated.

In the accompanying drawing, the attachment plug comprises a pair of insulating blocks 5 and 6 of the same contour, recessed.

on their meeting faces .to afiord suitable chambers for the electrical conductors housed therein. The present plug is of switch type, the switch mechanism not being shown, but being operated by the switch button 7. Conducting straps 8 and 9 lead It is the to the plug terminals to which my inven- 1 tion relates.

These terminals comprise a pair of plates 10 and 11 of identical shape, centrally channeled at 12 to afford, when juxtaposed, a more or less circular recess for the accommodation of a jack of the post type. The side margins 13 of the plates are maintained flat to bear against the marginal areas of a cooperating jack blade, while flanges 14 at one side o each plate form spacing elements which hold the plates suificiently far apart to permit the entrance of the blade, and at the same time aiford lateral guides which engage the edges of the jack blade and corn fine it within the terminal.

In order to make good electrical contact with a jack of either type, each plate is transversely slotted at 15 from one margin to form a series of spring fingers 16. The channel opening is less than the diameter of the usual post jack, and the spacing afforded by the side flanges 14 is less than the thickness of the usual blade jack, so that a good wiping contact between the jacks and the spring fingers 16 is secured by providing a spring band 17 surrounding the free ends of the juxtaposed plates 10 and 11 to hold the latter together. This spring band is kept in place on the one hand by tongues 18 struck outward from one of the spring fin gers and bearing against the inner edges of the spring band 17. The band is retained at its other edge by its engagement with the outwardly flared lips 19 at the entrance end of the terminal. These lips have thus the double function of retaining the spring band 17, and of affording a guide for the entering jack.

It will be noted that the recesses 20, in which the terminals are housed, are of sufficient area to permit the latter to expand against the action of the restraining spring 16, and also to move laterally therein to accommodate the terminals to the spacing of the cooperating jacks. In order to permit the lateral play of the terminals in their recesses 20, and at the same time to maintain the same in parallel, while also insuring a 7 ing block 6. To pievent the plates from behousing chambers 20, so as to maintain their parallel relationship irrespective of the spacing of the jacks. Good electrical connection with the end of the strap 8 or 9, underlying the head of the thimble 24, may

be assured by arranging} spring washer on the screw 22, or, more simpl by slotting the head flange of the thimbl e 24 and &- setting the tongue-26, so formed, which thus constitutes a spring brush contact which esv tablishes constantly a good. electrical connection between the plates and the straps 8 and 9. It will be noted, however, that'this spring may be omitted, since the entering jack spreads the plate sufliciently to. press the head of the thimble down upon the strap;

The terminals are readily made a from sheet metal, are readily assembled and secured in position, while the securing means is such that they maintain their parallelism at all spacings, firmly grip the inserted jack,

of whatever type, and maintain ood' electrical connectlon with the conducting straps 8 and 9, the insertion of the jacks assisting in the establishment of this connection.

r ship.

Various modifications in detail of construction will-readily occur tothose skilled in the art without departing from what I claim as'my invention.

I claim- 1. In' an attachment plu an insulating body, a pair of substantialfi parallel jackreceiving terminals freely housed therein, fixed conductors in electrical connection with said terminals, and securing means carried by the body and serving to hold said conductors in fixed position thereon, and also engaging said terminals, at leastLoneof said terminals having lateral play with respect to said securing means to permit variation in the spacing-of said terminals while maintaining their substantially parallel relation- .2," ing;a pair of opposed terminal plates a apted to receive between them a cooperating means at'said securing point electrically con- An attachment plug terminalcom risnecting the terminal plates to a conductor with freedom to separate at said connection under the action of an inserted jack.

3. An attachment plug terminal comprising a pair of opposed terminal plates adapt-z 7 ed to receive etween them a-cooperating jack, and means electrically connecting the same to a conductor with freedom to separate at said connection and to move laterally with relation thereto under the action of an inserted jack. P

4. An attachment plug "terminal'comprising a pair of opposed'independent terminal plates transversely slotted to afiord a series of spring fingers, a flat spring band surrounding the spring fingers at the jack-reeeiving end of the terminal, and means for holding said band in position on said plates.

-5. An attachment plug terminal comprising a air of opposed terminal plates with flared ips at the jack-receivmg end of the a terminal, spring band yieldingly uniting said plates'and engaging 'said lips at one edge, together with atongue struck from at least one. of said plates and engaging the other edge of said band to maintain the same in, position. 6. A connector terminal apertured to receive a binding screw, a bushing ,through which the screw passes, said bushing having a spring flangeoperative to maintain the terminal in frictional engagement with the head of the binding screw.

7. A connector terminal transversely slotted at oneend to accommodate. a binding screw passing therethrough, a bushing entering said slot and throughwhich the stem of the screw passes, said bushing having a spring flange underlying the terminal and serving to maintain ,the same'm frictional engagement. with the head of the binding 8. In an attachment plug, an insulatingcuring means uniting said terminals tothe conductors with freedom of lateral play to,

'vary their spacing, and spring means for insuring good electrical connection between said play.

In testimony whereof I have slgned my name to this specification.

GEORGE l3. THOMAS.

said conductor and terminals irrespective of 

